High permittivity low leakage capacitor and energy storing device

ABSTRACT

A method is provided for making a high permittivity dielectric material for use in capacitors. Several high permittivity materials in an organic nonconductive media with enhanced properties and methods for making the same are disclosed. A general method for the formation of thin films of some particular dielectric material is disclosed, wherein the use of organic polymers, shellac, silicone oil, and/or zein formulations are utilized to produce low conductivity dielectric coatings. Additionally, a method whereby the formation of certain transition metal salts as salt or oxide matrices is demonstrated at low temperatures utilizing mild reducing agents. Further, a circuit structure and associated method of operation for the recovery and regeneration of the leakage current from the long-term storage capacitors is provided in order to enhance the manufacturing yield and utility performance of such devices.

RELATED APPLICATION

This application is a divisional application and claims the benefit ofpriority of U.S. Nonprovisional application Ser. No. 12/245,665 filed 3Oct. 2008, which is a nonprovisional of and claims the benefit of andpriority to U.S. Provisional Application 60/978,067, filed 3 Oct. 2007,the entire contents of which are incorporated herein by this referenceand made a part hereof.

FIELD OF THE INVENTION

This disclosure relates generally to capacitors and storage devices.More specifically, this disclosure relates a high permittivity lowleakage capacitor and energy storing device, and methods for forming thesame.

BACKGROUND

In embodiments described herein, the following understanding of thenomenclature used in describing the present High Capacity Energy StorageCapacitors should be understood and considered. In older literature, theterm “dielectric constant” of a material is used to describe thepolarization ability or “permittivity” of the material when placed in anelectric field. The term “dielectric breakdown” was used to describe thevoltage at which an insulator material would “breakdown” and conductcurrent. This dielectric breakdown voltage is also known as thedielectric strength. Since the abbreviated version for both of theseterms is “dielectric,” and the material itself is called the dielectric,there was some confusion in the literature as to what was beingdiscussed. Thus, the term “permittivity” is now used (mostly) todescribe the ability of a material to charge polarize and change the“dielectric constant” of its volume of space to a higher value from thatof a vacuum. Dielectric breakdown voltage is sometimes used to indicatethe dielectric strength of the material.

The relative permittivity of a material is simply the measurement of itsstatic dielectric constant divided by the dielectric constant of vacuum.

$e_{r} = \frac{e_{s}}{e_{0}}$

where:

-   -   e_(r)=relative permittivity    -   e_(s)=measured permittivity    -   e_(o)=electrical permittivity of vacuum (8.8542 E-12 F/m)

Thus, when the term good dielectric is used, this is meant (usually) tomean a material that displays good electrical insulation characteristicssuch as a high breakdown voltage and a low conductivity. A material thathas a good “dielectric constant” for a capacitor means it has a good“permittivity” (high value) and increases the capacitance of a givensize capacitor when placed between the electrodes by a “good” (high)amount.

A capacitor is formed when two conducting plates are separated by anon-conducting media, called the dielectric. The value of thecapacitance depends on the size of the plates, the distance between theplates and the properties of the dielectric. The relationship is:

$C = \frac{{e_{0} \cdot e_{r}}A}{d}$

-   -   e_(o)=electrical permittivity of vacuum (8.8542 E-12 F/m)    -   e_(r)=relative permittivity    -   A=surface of one plate (both the same size)    -   d=distances between two plates

Whereas the electrical permittivity of a vacuum is a physical constant,the relative electrical permittivity depends on the material.

Typical Relative Electrical Permittivities Material e_(r) Vacuum  1Water 80.1 (20° C.) Organic Coating 4-8

A large difference is noticed between the electrical permittivity ofwater and that of an organic coating.

Relative Static Permittivities of Some Materials at Room Temperature

Material Dielectric Vacuum 1 (by definition) Air 1.00054Polytetrafluoroethylene 2.1 Polyethylene 2.25 Polystyrene 2.4-2.7 Paper3.5 Silicon dioxide 3.7 Concrete 4.5 Pyrex (glass) 4.7 (3.7-10) Rubber 7Diamond 5.5-10  Salt  3-15 Graphite 15-Oct Silicon 11.68 Methanol 30Furfural 42 Glycerol 47-68 Water 88-80.1-55.3-34.5 Hydrofluoric acid83.6 (0° C.) Formamide 84.0 (20° C.) Sulfuric acid 84-100 (20-25° C.)Hydrogen peroxide 128 aq-60 (−30-25° C.) Hydrocyanic acid 158.0-2.3(0-21° C.) Titanium dioxide  86-173 Strontium titanate 310 Bariumstrontium 15 nc-500 Barium titanate 90 nc-1250-10,000 (LaNb):(ZrTi)PbO3500, 6000

It is interesting to note that materials which have large dipole momentsand high permittivity are often conductive salts or very polar inorganicacids or bases. In these cases their liquid form is difficult to useand/or toxic or corrosive. This makes their utility difficult anddangerous. Often the polar salts display undesirable conductivity whenthey are slightly impure and/or exposed to atmospheric conditions withhumidity.

The inorganic salts which display nonconductive behavior and very highpermittivities are inorganic salts of the transition metals and otherinorganic salts that display high permittivities due to their crystallattice structures. Use of these materials are difficult due to theircrystalline nature. Much effort has been expended to make these types ofmaterial more manufacturable through the use of thin coatings andmethods of high temperature fusing and sintering.

SUMMARY OF THE INVENTION

According to one or more features of the disclosure, a method isprovided for making a high permittivity dielectric material for use incapacitors. Several high permittivity materials in an organicnonconductive media with enhanced properties and methods for making thesame are disclosed.

According to one or more features of the disclosure, a general methodfor the formation of thin films of some particular dielectric materialis disclosed, wherein the use of organic polymers, shellac, siliconeoil, and/or zein formulations are utilized to produce low conductivitydielectric coatings. Additionally, in accordance with one or morefeatures of the disclosure, a method whereby the formation of certaintransition metal salts as salt or oxide matrices is demonstrated at lowtemperatures utilizing mild reducing agents.

Additionally, in accordance with one or more features of the disclosure,a circuit structure and associated method of operation for the recoveryand regeneration of the leakage current from the long-term storagecapacitors is provided in order to enhance the manufacturing yield andutility performance of such devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned features and objects of the present disclosure willbecome more apparent with reference to the following description takenin conjunction with the accompanying drawings wherein like referencenumerals denote like elements and in which:

FIG. 1 is an exemplary flow chart illustrating a method for making ahigh permittivity dielectric material, according to an embodiment of thepresent disclosure.

FIG. 2A illustrates a multi-state electrical circuit diagram inaccordance with one or more embodiments of the present disclosure forthe recovery of leakage current from an energy storage capacitor.

FIG. 2B illustrates a multi-state electrical circuit diagram inaccordance with one or more embodiments of the present disclosure forthe recovery of leakage current from an energy storage capacitor.

FIG. 2C illustrates a multi-state electrical circuit diagram inaccordance with one or more embodiments of the present disclosure forthe recovery of leakage current from an energy storage capacitor.

FIG. 2D illustrates a multi-state electrical circuit diagram inaccordance with one or more embodiments of the present disclosure forthe recovery of leakage current from an energy storage capacitor.

FIG. 3 is an exemplary flow chart illustrating a method for recovery andregeneration of a leakage current from a capacitor using the multi-stateelectrical circuit of FIGS. 2A-D, according to an embodiment of thepresent disclosure.

FIG. 4 is a cross-sectional view of a high permittivity low leakagecapacitor, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to a method of forming a highpermittivity low leakage capacitor and energy storing device.

In one or more embodiments, the methods, materials and devices describedin the present disclosure reduce the difficulties associated with themanufacture of high permittivity materials, decrease the difficulty ofincorporation of these materials into devices, increase the performanceof the materials, and show a method whereby the materials performancemay be enhanced through the use of external electronic components toincrease the reliability and longevity of the device. A result of theseimprovements will be a decrease in the rejection ratio of such deviceswhen manufactured and also to improve the long term reliability of thedevices when in actual use. Also, the use of the methods set forth inthe present disclosure will also reduce the manufacturing costs of thematerials and devices and aid in the reduction of waste byproducts thatwould otherwise go unused for such applications.

When considering capacitors and their relationships to energy, todetermine the work that must be done to charge a capacitor (i.e. thepotential energy=E), the work performed is equal to the potential energystored in the capacitor. The work performed to transfer a given amountof charge into a given capacitance is given by the following formula:

$W = \frac{q^{2}}{C \cdot 2}$

where the relationship between capacitance and charge is:

-   -   q=C·V    -   where q=charge (coulombs)    -   C=capacitance (Farads)    -   V=electric potential (volts).

Thus, substitution for q in the work equation above provides,

$E = {W = \frac{C \cdot V^{2}}{2}}$

where E is the energy stored in the capacitor and is equal to the workthat was performed to store the charge on the capacitor.

Thus, it should be noted that the energy stored in a capacitor isrelated to the square of the voltage applied to the capacitor.

In one or more embodiments, it is therefore important that the voltagerating for the capacitor be as high as possible when energy storage isthe primary use for the device. In one or more embodiments, besideshaving a high break down voltage, the capacitor also possesses a lowleakage current. In other words, when the capacitor has been charged toa given voltage, the rate of charge conduction from one electrode to theother should be a relatively small value. When the capacitor is chargedfor energy storage over some given period of time, the rate of leakageis an acceptably low enough value that would vary depending on the useof the storage device (how long is it stored) and the “value” of theenergy thus stored (how easy is it to recharge and the cost of thecharge). An acceptable value for leakage would typically vary greatlyfrom application to application. In all embodiments, leakage issomething that is generally avoided and minimized.

In one or more embodiments, the highest value of relative permittivityand the highest voltage rating possible for a given level of leakageprovides the best capacitor when evaluated for most energy storageapplications. It should also be noted that the ability of the capacitorto “absorb” charge at a reasonable rate is also an important factor. Formost electronic applications the ability of a capacitor to act as anideal capacitor is an important parameter, especially when working atfrequencies in the MHz and above. The capacitor should also have theability to fully discharge the charge that has been placed into itselectrodes. All capacitive device suffer from “irreversible dielectricabsorption”, but in the field of energy, discharging a capacitor to acertain level that is determined by its application will place a limiton how much of this effect is acceptable.

In one or more embodiments, substantial improvements in the voltagerating, leakage current, and dielectric of an energy storage capacitorare provided. The scope of the improvements are generally describedherein as they relate to the field of energy storage, but the methodsand devices described herein can further be applied to generalapplications wherein such improvements can be utilized to make a devicethat displays enhanced characteristics, including better frequencyresponse and reduced dielectric absorption in other applications for thematerials and device described herein.

In one or more embodiments, a high permittivity low leakage capacitorand energy storage device is described having the following improvedcharacteristics:

1) High voltage rating (High break-down voltage),

2) High relative permittivities,

3) Low leakage current at maximum voltage charge,

4) Small size and weight,

5) Safe use due to low toxicity and other hazards,

6) Easy and better manufacturing procedures,

7) Environmentally friendly manufacturing,

8) High rate of discharge and charge, and

9) Ability to fully discharge.

It should be noted that previously known high permittivity materialshave been subject to aging and brittleness, thereby providingsubstantial difficulty in forming such materials into the requiredshapes for their various uses. Further, since several of thesepreviously known high permittivity materials are toxic, conventionalmachining and forming steps are deemed undesirable in a normal workenvironment. Due to their mechanical instability, the previously knownhigh permittivity materials were also prone to electrical fatigue andmechanical fatigue when subjected to repeated electrical activations.Also, previously known high permittivity materials needed to beprotected from the environmental changes, such as humidity changes, thatcan lead to microfractures in the material and subsequent electricalfailures. There was also a need to form previously known highpermittivity materials at high temperatures. Due to their somewhatcomplex crystalline structures and need to be formed at hightemperature, it has traditionally been difficult to make highpermittivity materials into thin films. Often the crystal structureswere poorly formed and the thin films showed reduced permittivities asthin films versus their bulk property.

To alleviate these mechanical and electrical problems, in one or moreembodiments, a permittivity material is provided that is mechanicallyground and dispersed into an organic polymer for low temperatureprocessing (i.e., temperature processing below approximately 500° C.).In different embodiments described herein, a variety of materials aredescribed as being mixed and suspended in various polymers that possessthe desired enhanced characteristics. In one or more embodiments,shellac and zein are found to offer enhanced properties for thisapplication. In the case of both of these materials, the water andalcohol solubility of the polymer precursors provide desirableproperties.

In one or more embodiments, using the mechanically ground dielectrics,the suspension of the permittivity of the dielectric in the organicbinder was enhanced by approximately 25% in shellac and zein over theirdry particulate forms.

In one or more embodiments, an in situ formation of the dielectric wasalso performed to produce unique dielectrics possessing uniquecharacteristics. In these embodiments, the addition of NaBH₄ in analcoholic solution of zein was used to produce and enhance thefunctionality of the mixture. The resulting mixture, when treated withconcentrated ammonium hydroxide and then heated, produces greatlyenhanced dielectric material with permittivity increases on the order of250% based on their change in permittivity from their simply being mixedwith the organic binders. While even greater optimization may beachieved with further experimentation, the viability of the procedureand its substantial utility have been shown by the resulting propertiesof such a mixture.

In one or more embodiments, the dielectric compounds when suitablyground may alternatively be mixed with silicone oil and a small amountof borax or sodium borohydride. When heated to 150° C., similar resultsof increases up to 250% as when the organic polymer suspensions wereused.

In both of the above-described embodiments, when the mixtures wereplaced between two electrodes in a capacitor arrangements, the use ofeither the shellac, zein, or silicone oil polymers resulted inundetectable leakage currents when the voltage between the electrodeswas raised to 300V. To the contrary, when dielectric material such asbarium titanate was ground and pressed in between the electrodes, itshowed unacceptable leakage currents when tested.

The following representative embodiments will set forth specificexamples of methods of making a high permittivity material in accordancewith the present disclosure. It is understood that the disclosure neednot be limited to the disclosed embodiments but it is intended to covervarious modifications thereof, including combinations of the steps andcomponents of the various examples.

Procedures:

I. Procedure for Making a Reduced Leakage Current Dielectric for Use ina Capacitor or Energy Storage Device.

In one or more embodiments, 1.5 g of zein is added to 15 mL of ethanol.A small amount of water is added or optionally the solution is filteredor centrifuged to remove any undissolved particulate matter. Theresulting clear solution is then treated with 0.5 g to 15 grams of highpermittivity inorganic salt such as barium titanate powder that has beenpreviously treated to be made into a nano powder or other finedispersion material. The resulting slurry is then mixed thoroughly andscreened or otherwise spread on the target electrode. Addition of asmall amount of DMSO (Dimethylsulfoxide) or DMF (dimethyl formamide)will facilitate the screening and drying process. The “green sheet”material may then be dried at low temperature or alternatively clampedor otherwise pressed in contact with the other plate electrode. Elevateddrying temperatures of not over approximately 60° C. (as excessivetemperature can lead to bubble formation and cavitation of the film) arethen maintained until all solvents have been removed. Further heating at150° C. can be performed.

II. Procedure for Making a High Permittivity Dielectric Utilizing LowTemperature Methods

In one or more embodiments, 0.75 g of strontium II carbonate is added toa stirred solution of 1.5 g gadolinium III carbonate in 15 mL of DIwater. After dissolution of the two compounds takes place, a solution of200 mg of zein (or other organic polymer) in 2 mL of water with 200 mGof sodium borohydride is added dropwise to the metal solution with goodstirring. The organic polymer material is optional if the dielectricmaterial is to be formed or isolated without binder. A small amount ofacetic acid may be added to facilitate the reduction. After 5 minutes 5mL of concentrated ammonium hydroxide is added. After 5 more minutes,the solution may be filtered and then screened, spread, or spun coatedonto the desired electrode material and evaporated and treated asdescribed in Procedure I. Or the solution can be evaporated to isolatedthe dielectric material as a solid.

III. Procedure for Reducing the Leakage Current in a Dielectric that hasa Small Amount of Conductivity

In one or more embodiments, 1.5 G of Zein is dissolved in 15 mL ofethanol. A 5 to 50 mL slurry of the desired dielectric material is thentreated with the zein solution with good agitation. The slurry may thenbe spread, screened, or spun coated onto the electrode and treated asdescribed in procedure I to produce a device.

IV. Procedure for Reducing the Leakage Current Utilizing Shellac and aHigh Permittivity Material

In one or more embodiments, to a 1.5 G sample of the high permittivitymaterial as produced by a procedure herein wherein the dielectric isisolated as a solid powder or in liquid form is added 1.5 G ofcommercial grade shellac solution that has been filtered or centrifugedto remove particulate matter. Additional ethanol can be added as neededto make the material into a workable slurry or solution. The resultingliquefied material can then be spread, screened or spun coated onto theelectrode material as noted in procedure I.

V. Procedure for the use of Silicone Oil and a Dielectric Material as aCapacitor

In one or more embodiments, 1.0 G of silicone oil is added to a finelyground high permittivity dielectric of weight from 0 to 5 G. The mixtureis well stirred and a small amount of sodium borohydride or borax salt(0 to 500 mg) is added to the slurry or solution. If the solution ormixture is workable, it can then be spread, screened, or spun, onto anelectrode. The sheet can then be heated to approximately 150° C. to 300°C. for a few minutes to facilitate the increase in viscosity of thesilicone oil. The top electrode can then be pressed or otherwisefastened with pressure to the silicone formed electrode and then heattreated for a period of time sufficient to fully stabilize thedielectric material. For example, approximately three hours at 150 to200° C. is sufficient, although less time and different temperatures maybe acceptable.

FIG. 1 is an exemplary flow chart illustrating a method for making ahigh permittivity dielectric material, according to an embodiment of thepresent disclosure. The method begins by dissolving an organic polymerin a solvent to form a slurry solution (105). The solvent may beshellac, silicone oil and/or zein. In one embodiment, the undissolvedorganic polymer is removed from the slurry solution (110), for example,using a filter or centrifuge. An inorganic salt may then be added to theslurry solution (115). The inorganic salt may be a transition metalsalt, such as a Gd, Sr, Sn, and/or Fe salt. In one embodiment, abreakdown voltage adjuvant may be added to the slurry solution (120).The breakdown voltage adjuvant may include one or more of Y, Ni, Sm, Sc,Tb, Yb, La, Te, Ti, Zr, Ge, Mg, Pb, Hf, Cu, Ta, Nb, and/or Bi. Tofacilitate screening and drying, a dimethyl formamide and adimethylsulfoxide may be added to the slurry solution (125). The slurrysolution may then be heated to a temperature of about 150° C. to about300° C. to remove or evaporate the solvent (130).

Referring now to FIGS. 2A-2D, a multi-state electrical circuit diagramis illustrated in various states in accordance with one or moreembodiments for making an electronic device for the recovery of leakagecurrent from an energy storage capacitor. FIGS. 2A-2D illustrates fourstates a novel circuit that has been developed to regenerate and recyclethe leakage current from a capacitor or capacitor array, C1.

In FIGS. 2A-2D, the following components are described. C1 is acapacitor or capacitor array that is capable of storing a certain amountof charge. It displays a leakage of current when subjected to a givenvoltage (V+). C2 is a capacitor (e.g., much smaller than C1) of goodcharacteristics that displays a much lower leakage current (or could bethe same leakage current, but of much smaller area of capacitance). D1is a diode that has the characteristic of being able to “block” thevoltage from C1 from returning to Vss. When the voltage output from T1'ssecondary exceeds the voltage present on C1 and the forward voltage dropof D1, then current will conduct to the C1 capacitor(s).

S1 is switch that is able to electrically connect the high voltage sideof C1 to the charging voltage, V+. In one position it is connected to V+and in the other position it is an open connection or connected to theload. S2 and S3 are electrically controlled switches that have theability to switch between two different outputs. These switches do notnecessarily need to be high voltage switches able to withstand V+. T1 isa “flyback” type of transformer or an equivalent inductor that has thecapability of withstanding a voltage on the secondary winding that is asgreat or greater than V+. V+ is a charging voltage that is connected tothe main energy storage capacitor(s) C1 during the charge cycle. Vss isthe lower voltage that is present on the opposite electrode of C1 fromV+ that produces the potential difference between the two.

FIG. 3 is an exemplary flow chart illustrating a method for recovery andregeneration of a leakage current from capacitor C1 using themulti-state electrical circuit of FIGS. 2A-2D, according to anembodiment of the present disclosure. Referring to State A of thecircuit diagram of FIG. 2A, a current is shown flowing from V+ sourcethrough S1 to the positive plate of C1 (305). In this situation S2 isconnected to Vss so that the charge can be accumulated on C1 to thepotential difference between the two (310). The status of S3 does notmatter at this state and no current is flowing in the lower part of thecircuit.

In State B of the circuit diagram of FIG. 2B, V+ has been disconnectedfrom the positive plate of C1 and the other plate of C1 is connected toground through S2. This illustrates a typical situation where the storedload of the C1 cap is being used through the S1 switch to power a load.

In States C and D of the circuit diagram of FIG. 2C, two states areshown where the C1 storage capacitor is not being charged or discharged.However, due to the leakage current from one plate to another, there isa current flowing through the non-ideal C1 component to C2 through theS2 switch (315). This current will charge C2 to some voltage at a ratebased on the relative capacitances of C1 and C2 and the rate of leakage(320). The switch S2 is disconnected from ground and connected to theinput of C2 (315). While in State C, the C2 capacitor is charged to somepredetermined voltage (V1). At that predetermined voltage, thecomparator then disconnects C2 from C1's open “Vss” plate using S2, andthen subsequently connects the positive plate of C2 to the input of T1transformer using S3, as shown in State D of FIG. 2D (325). Thisdischarge current through T1 induces a voltage on the secondary of T1that rises to a voltage value sufficient to return some of the charge toC1 through the diode D1 (325). Once the discharge of C2 is complete asdetermined by the comparator's determination of voltage on the positiveplate of C2, the comparator returns all the switches to State C unless ademand is made to charge or discharge C1.

In the above-described operation, a relative “leaky” capacitor canreturn some of the charge loss through the C1's leakage when C1 is notin use during either a charge or discharge period of time. Due to theefficiency of the circuit (which can be made to be >90% efficiency), theleakage from the C1 device is effectively reduced by a factor of10.times. For production of a large array of capacitors, this can be asignificant improvement in yield. Often there are unwanted impurities inthe material that increase the leakage current, and these are often notdetected until the entire assembly has been completed. In a large arraycapacitor, this amounts to a significant number of good devices beingrejected due to a relatively small number of failures in the array.

In one or more embodiments, energy storage is the intended use for thiscircuit, such that it is likely that relatively large periods of timewill elapse between demands for energy charging or energy discharging.During those States (A & B), the recharge circuit cannot be used asdescribed.

As can be seen from the foregoing description, the present method avoidsthe high temperature methods associated with prior high permittivitymaterials by the use of organic substrates to suspend and coat the highdielectric materials. High process temperatures are also avoided by thepresent methods. In addition, a new method for making high permittivitymaterials is disclosed and when used in conjunction with the highbreakdown voltage materials (such as zein), a process for making a highdielectric capacitor with a high breakdown voltage character is madepossible.

Due to the nature of the process, the procedure is rugged in terms ofcontrol of leakage current. The coating material is a general materialthat seems to coat any material, including contamination materials andit thus will thereby make manufacture of the device easier and withbetter yields. Since it is difficult to make most good high permittivitydielectrics pure enough to display low conductivity (and thus producinghigh leakage currents), the use of organic binders in a matrix of highpermittivity material is desirable because the contact of a conductivecontamination or a defective crystal that may have conductivity isprevented by the coating of organic substrate.

FIG. 4 is a cross-sectional view of a high permittivity low leakagecapacitor, according to an embodiment of the present disclosure. Asillustrated, the capacitor electrode 10 and its opposite polarityelectrode 11 are spaced apart approximately equally. In the interveningspace are heterogeneous dielectric materials 12 and 13. In oneembodiment, a dielectric material may be formed from existing materialssuch as barium titanate or other such known high dielectrics, with aninsulation material 13 such as zein, shellac, crosslinked silicones, orother such materials, to fill the intervening spaces between the highdielectric material 12. Due to the improvements of this invention, a lowtemperature process using the insulation dielectric 13 can incorporaterelatively low temperature stability and melting materials.

The methods described herein provide a unique approach for making highpermittivity capacitors without having to resort to standard hightemperature manufacturing methods that almost no organic compound canwithstand. This new approach vastly expands the materials by which thesecapacitors can be made, and increases the performance of the capacitorsdue to the reduced leakage currents that many organic polymers candisplay.

In one or more embodiments, Gd, Sr, Sn and Fe may be utilized as highpermittivity dielectrics. In one or more embodiments, shellac, zein andsilicon oil may be used as high voltage breakdown adjuvants. In otherembodiments, other dielectrics and some breakdown voltage enhancers(adjuvants) may be utilized, such as but not limited to Y, Ni, Sm, Sc,Tb, Yb, La, Te, Ti, Zr, Ge, Mg, Pb, Hf, Cu, Ta, Nb, Bi.

Additionally an electronic circuit is shown wherein the leakage currentfor the device when in the unused and stored state can be “feed back”into the voltage charge of the primary energy storage unit. This willextend the life of the charge in the capacitor and also increase theyield from the manufacturing process.

While the system and method have been described in terms of what arepresently considered to be specific embodiments, the disclosure need notbe limited to the disclosed embodiments. It is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the claims, the scope of which should be accorded the broadestinterpretation so as to encompass all such modifications and similarstructures. The present disclosure includes any and all embodiments ofthe following claims.

What is claimed is:
 1. A method comprising: recovering and regeneratinga leakage current from a first capacitor having a first electrode and asecond electrode, by applying a voltage to the first capacitor through afirst switch selectively connected to a charging voltage and the secondelectrode of the first capacitor; storing charge corresponding to theapplied voltage in the first capacitor; controlling a second switch toallow a leakage current to flow from the first capacitor to a secondcapacitor, the second switch being selectively connected to the secondelectrode of the first capacitor and to the second capacitor; storingcharge corresponding to the leakage current of the first capacitor inthe second capacitor; and controlling a third switch to allow chargefrom the second capacitor that corresponds to the leakage current of thefirst capacitor to flow back to the first capacitor to increase theefficiency and enhance the performance of the first capacitor.
 2. Themethod of claim 1, wherein the second capacitor has a lower leakagecurrent than the leakage current of the first capacitor.
 3. The methodof claim 1, further comprising selectively controlling the second switchto allow a leakage current to flow from the first capacitor to thesecond capacitor when the first capacitor is not being charged ordischarged.
 4. The method of claim 3, further comprising comparing thecharge stored in the second capacitor against a predetermined voltageand disconnecting the second switch to cause the second capacitor todischarge its stored charge once the stored charge reaches thepredetermined voltage.
 5. The method of claim 4, further comprisingallowing the current produced by the discharge of the second capacitorto pass through a transformer coupled between the first capacitor andthe second capacitor by the third switch, thereby inducing a voltage inthe transformer and increasing the induced voltage to a value sufficientto deliver charge back to the first capacitor.
 6. A storage devicecomprising: a first capacitor having a first electrode and a secondelectrode, wherein the first capacitor possesses a leakage current whenthe first capacitor is not being charged or discharged; a first switchcapable of selective connecting or disconnecting the first electrode ofthe first capacitor to a charging voltage; a second capacitor,electrically coupled to the first capacitor, wherein the secondcapacitor is capable of collecting the leakage current from the firstcapacitor; a second switch electrically connected to the secondelectrode of the first capacitor and to the second capacitor, the secondswitch capable of selectively controlling the flow of the leakagecurrent from the first capacitor to the second capacitor when the firstcapacitor is not being charged or discharged, wherein a charge can bestored in the second capacitor corresponding to the leakage currentreceived from the first capacitor; and a third switch capable ofselectively delivering current produced from a discharge of the secondcapacitor back to the first capacitor to increase the efficiency andenhance the performance of the first capacitor.
 7. The storage device ofclaim 6, wherein the second switch is capable of selectively connectingthe first capacitor to a ground when the first capacitor is disconnectedfrom the charging voltage by the first switch.
 8. The storage device ofclaim 6, further comprising a transformer coupled between the firstcapacitor and the second capacitor by the third switch, the transformercapable of receiving the current discharged from the second capacitorand capable of producing an output voltage sufficient to deliver chargeback to the first capacitor, thereby transmitting a certain fraction ofthe leakage current output by the first capacitor back to the firstcapacitor, through the second capacitor and the transformer.
 9. Thestorage device of claim 8, further comprising a diode positioned betweenthe transformer and the first capacitor.
 10. The storage device of claim6 further comprising a comparator capable of comparing the charge storedin the second capacitor against a predetermined voltage and causing thesecond capacitor to discharge its stored charge once the stored chargereaches the predetermined voltage.
 11. The storage device of claim 6,wherein the second capacitor has a lower leakage current than theleakage current of the first capacitor.
 12. The storage device of claim6, wherein the first capacitor further comprises a solid-state, highpermittivity material between the first and second electrodes, the highpermittivity material being a mixture of an organic polymer andinorganic salt including a boron compound wherein the inorganic salt issodium borohydride (NaBH₄), borax, or a mixture thereof.